I am trying to learn to use the simulink model linearizer to obtain a transfer function from the following simplified model in MATLAB 2020b:

If I understand the manual correctly, in order to obtain the closed-loop transfer function of the full loop PI/(1+PI*Feedback), the complementary sensitivity analysis point should be applied here:

When applying this at the model output and running the linearizer, the following tf is obtained:

However, the result differs from my own calculations.
When I apply the open-loop input and output however to the loop as follows:

This seems to give me the correct result:

Using these is not always possible in my other complex model however, without ripping it apart. The way I understand the manual, both approaches should be identical. Where am I wrong, what does the complementary sensitivity yield here and what would be the correct way of obtaining the closed loop tf?

My sincere thanks for helping me out with this one…I am trying to learn to use the simulink model linearizer to obtain a transfer function from the following simplified model in MATLAB 2020b:

If I understand the manual correctly, in order to obtain the closed-loop transfer function of the full loop PI/(1+PI*Feedback), the complementary sensitivity analysis point should be applied here:

When applying this at the model output and running the linearizer, the following tf is obtained:

However, the result differs from my own calculations.
When I apply the open-loop input and output however to the loop as follows:

This seems to give me the correct result:

Using these is not always possible in my other complex model however, without ripping it apart. The way I understand the manual, both approaches should be identical. Where am I wrong, what does the complementary sensitivity yield here and what would be the correct way of obtaining the closed loop tf?

My sincere thanks for helping me out with this one… I am trying to learn to use the simulink model linearizer to obtain a transfer function from the following simplified model in MATLAB 2020b:

If I understand the manual correctly, in order to obtain the closed-loop transfer function of the full loop PI/(1+PI*Feedback), the complementary sensitivity analysis point should be applied here:

When applying this at the model output and running the linearizer, the following tf is obtained:

However, the result differs from my own calculations.
When I apply the open-loop input and output however to the loop as follows:

This seems to give me the correct result:

Using these is not always possible in my other complex model however, without ripping it apart. The way I understand the manual, both approaches should be identical. Where am I wrong, what does the complementary sensitivity yield here and what would be the correct way of obtaining the closed loop tf?

My sincere thanks for helping me out with this one… model linearizer, transfer function, simulink MATLAB Answers — New Questions

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